The present invention relates to a facility for removing layers that are electro-deposited onto cathodes, and is particularly applicable to the situation where metals, such as copper and zinc, are deposited by electrolysis.
More specifically, the present invention relates to the type of facility that includes an area for the reception of cathodes coming from the electrolytic vats, a cathode treatment area, and a storage area for cathodes free from the electrolytic metal layer. The cathodes may be moved consecutively from one of these areas to the other. The treatment area includes apparatus to wash the cathodes and to remove the electro-deposited metal layers.
Generally, in these types of facilities, the apparatus for washing the cathodes are stationary water jets directed at the cathodes. The operation to remove the electro-deposited metal layers are carried out in two successive operations. In the first operation, the upper edge of the electro-deposited layer is separated from the cathode plate, and in the second operation the cathode plates are totally separated from the electro-deposited layers.
In a known facility for the electrolytic deposition of zinc, a penetrator is used in the first operation to separate the upper edge of the electro-deposited layer from the cathode plate, and in the second operation are used to totally remove the electro-deposited layer from the cathode. A facility of this type is described, for example, in Spanish Patent No. 2020729 by the applicants of the present invention.
The electrolytic deposition of copper is described in Spanish Patent No. 2005573, of MIM Technology Marketing Ltd. In the procedure of that patent, the first stage of separation proceeds by subjecting the cathode to bending so as to enable at least part of the electro-deposited metal layer to separate from the cathode. In the following stage the electro-deposited layer is completely removed by the use of claws or gas jets.
Whichever may be the system selected, the complete removal of the electro-deposited metal layer from the cathode requires two successive operations. These operations and the facilities for performing these operations are very costly because of the equipment required.
In additions, in these procedures which involve the bending of the cathode in the first stage, there is a risk of causing the protection on the edges of the cathode from separating from the cathode. This may result in the entry of fluid between the protection and cathode during the electrolytic process, which results in the deposition of metal in these areas of the cathode.